This paper has data on employment, accidents, and so on across the mines. According to the study: "Comparing these [accident] figures with the total number of employees for each mine in Table 3 and 4 above, NFCA [the Chinese copper company] has the highest accident rate for all the mines in the country" (p. 12).

A Zambian official said: “Safety records for most companies have drastically gone down, with most companies recording slightly higher levels of accidents. For example, the Chinese have the worst safety record. In some of these mines, you find the boss himself is going underground with flipflops”.

Conditions of work are bad in a number of non-Chinese mines, especially for contract workers:

"For example, Bresmar Investment Limited, a contractor company with Kansanshi Mine in Solwezi, has reduced wages for its workers from K3,600 per hour to K2,900.40 per hour. These workers toil for 12 hours a day for seven (7) continuous days and rest for four (4) days."

I found out about this study via an April 8, 2012 posting by Research for Development at the Rural Modernity blog.